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Commit 899edae6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'perf-fixes-for-linus' of... 

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf, x86: Try to handle unknown nmis with an enabled PMU
  perf, x86: Fix handle_irq return values
  perf, x86: Fix accidentally ack'ing a second event on intel perf counter
  oprofile, x86: fix init_sysfs() function stub
  lockup_detector: Sync touch_*_watchdog back to old semantics
  tracing: Fix a race in function profile
  oprofile, x86: fix init_sysfs error handling
  perf_events: Fix time tracking for events with pid != -1 and cpu != -1
  perf: Initialize callchains roots's childen hits
  oprofile: fix crash when accessing freed task structs
parents c8c727db 4177c42a

arch/x86/kernel/cpu/perf_event.c

+46 −13
Original line number Diff line number Diff line
@@ -1154,7 +1154,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs) 
		/*

		 * event overflow

		 */

		handled		= 1;

		handled++;

		data.period	= event->hw.last_period;



		if (!x86_perf_event_set_period(event))
@@ -1200,12 +1200,20 @@ void perf_events_lapic_init(void) 
	apic_write(APIC_LVTPC, APIC_DM_NMI);

}



struct pmu_nmi_state {

	unsigned int	marked;

	int		handled;

};



static DEFINE_PER_CPU(struct pmu_nmi_state, pmu_nmi);



static int __kprobes

perf_event_nmi_handler(struct notifier_block *self,

			 unsigned long cmd, void *__args)

{

	struct die_args *args = __args;

	struct pt_regs *regs;

	unsigned int this_nmi;

	int handled;



	if (!atomic_read(&active_events))

		return NOTIFY_DONE;
@@ -1214,22 +1222,47 @@ perf_event_nmi_handler(struct notifier_block *self, 
	case DIE_NMI:

	case DIE_NMI_IPI:

		break;



	case DIE_NMIUNKNOWN:

		this_nmi = percpu_read(irq_stat.__nmi_count);

		if (this_nmi != __get_cpu_var(pmu_nmi).marked)

			/* let the kernel handle the unknown nmi */

			return NOTIFY_DONE;

		/*

		 * This one is a PMU back-to-back nmi. Two events

		 * trigger 'simultaneously' raising two back-to-back

		 * NMIs. If the first NMI handles both, the latter

		 * will be empty and daze the CPU. So, we drop it to

		 * avoid false-positive 'unknown nmi' messages.

		 */

		return NOTIFY_STOP;

	default:

		return NOTIFY_DONE;

	}



	regs = args->regs;



	apic_write(APIC_LVTPC, APIC_DM_NMI);



	handled = x86_pmu.handle_irq(args->regs);

	if (!handled)

		return NOTIFY_DONE;



	this_nmi = percpu_read(irq_stat.__nmi_count);

	if ((handled > 1) ||

		/* the next nmi could be a back-to-back nmi */

	    ((__get_cpu_var(pmu_nmi).marked == this_nmi) &&

	     (__get_cpu_var(pmu_nmi).handled > 1))) {

		/*

	 * Can't rely on the handled return value to say it was our NMI, two

	 * events could trigger 'simultaneously' raising two back-to-back NMIs.

		 * We could have two subsequent back-to-back nmis: The

		 * first handles more than one counter, the 2nd

		 * handles only one counter and the 3rd handles no

		 * counter.

		 *

	 * If the first NMI handles both, the latter will be empty and daze

	 * the CPU.

		 * This is the 2nd nmi because the previous was

		 * handling more than one counter. We will mark the

		 * next (3rd) and then drop it if unhandled.

		 */

	x86_pmu.handle_irq(regs);

		__get_cpu_var(pmu_nmi).marked	= this_nmi + 1;

		__get_cpu_var(pmu_nmi).handled	= handled;

	}



	return NOTIFY_STOP;

}

arch/x86/kernel/cpu/perf_event_intel.c

+9 −6
Original line number Diff line number Diff line
@@ -712,7 +712,8 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 
	struct perf_sample_data data;

	struct cpu_hw_events *cpuc;

	int bit, loops;

	u64 ack, status;

	u64 status;

	int handled = 0;



	perf_sample_data_init(&data, 0);
@@ -728,6 +729,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 


	loops = 0;

again:

	intel_pmu_ack_status(status);

	if (++loops > 100) {

		WARN_ONCE(1, "perfevents: irq loop stuck!\n");

		perf_event_print_debug();
@@ -736,19 +738,22 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 
	}



	inc_irq_stat(apic_perf_irqs);

	ack = status;



	intel_pmu_lbr_read();



	/*

	 * PEBS overflow sets bit 62 in the global status register

	 */

	if (__test_and_clear_bit(62, (unsigned long *)&status))

	if (__test_and_clear_bit(62, (unsigned long *)&status)) {

		handled++;

		x86_pmu.drain_pebs(regs);

	}



	for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {

		struct perf_event *event = cpuc->events[bit];



		handled++;



		if (!test_bit(bit, cpuc->active_mask))

			continue;
@@ -761,8 +766,6 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 
			x86_pmu_stop(event);

	}



	intel_pmu_ack_status(ack);



	/*

	 * Repeat if there is more work to be done:

	 */
@@ -772,7 +775,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 


done:

	intel_pmu_enable_all(0);

	return 1;

	return handled;

}



static struct event_constraint *

arch/x86/kernel/cpu/perf_event_p4.c

+1 −1
Original line number Diff line number Diff line
@@ -692,7 +692,7 @@ static int p4_pmu_handle_irq(struct pt_regs *regs) 
		inc_irq_stat(apic_perf_irqs);

	}



	return handled > 0;

	return handled;

}



/*

arch/x86/oprofile/nmi_int.c

+17 −5
Original line number Diff line number Diff line
@@ -568,8 +568,13 @@ static int __init init_sysfs(void) 
	int error;



	error = sysdev_class_register(&oprofile_sysclass);

	if (!error)

	if (error)

		return error;



	error = sysdev_register(&device_oprofile);

	if (error)

		sysdev_class_unregister(&oprofile_sysclass);



	return error;

}
@@ -580,8 +585,10 @@ static void exit_sysfs(void) 
}



#else

#define init_sysfs() do { } while (0)

#define exit_sysfs() do { } while (0)



static inline int  init_sysfs(void) { return 0; }

static inline void exit_sysfs(void) { }



#endif /* CONFIG_PM */



static int __init p4_init(char **cpu_type)
@@ -695,6 +702,8 @@ int __init op_nmi_init(struct oprofile_operations *ops) 
	char *cpu_type = NULL;

	int ret = 0;



	using_nmi = 0;



	if (!cpu_has_apic)

		return -ENODEV;
@@ -774,7 +783,10 @@ int __init op_nmi_init(struct oprofile_operations *ops) 


	mux_init(ops);



	init_sysfs();

	ret = init_sysfs();

	if (ret)

		return ret;



	using_nmi = 1;

	printk(KERN_INFO "oprofile: using NMI interrupt.\n");

	return 0;

drivers/oprofile/buffer_sync.c

+14 −13
Original line number Diff line number Diff line
@@ -141,16 +141,6 @@ static struct notifier_block module_load_nb = { 
	.notifier_call = module_load_notify,

};





static void end_sync(void)

{

	end_cpu_work();

	/* make sure we don't leak task structs */

	process_task_mortuary();

	process_task_mortuary();

}





int sync_start(void)

{

	int err;
@@ -158,7 +148,7 @@ int sync_start(void) 
	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))

		return -ENOMEM;



	start_cpu_work();

	mutex_lock(&buffer_mutex);



	err = task_handoff_register(&task_free_nb);

	if (err)
@@ -173,7 +163,10 @@ int sync_start(void) 
	if (err)

		goto out4;



	start_cpu_work();



out:

	mutex_unlock(&buffer_mutex);

	return err;

out4:

	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
@@ -182,7 +175,6 @@ int sync_start(void) 
out2:

	task_handoff_unregister(&task_free_nb);

out1:

	end_sync();

	free_cpumask_var(marked_cpus);

	goto out;

}
@@ -190,11 +182,20 @@ int sync_start(void) 


void sync_stop(void)

{

	/* flush buffers */

	mutex_lock(&buffer_mutex);

	end_cpu_work();

	unregister_module_notifier(&module_load_nb);

	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);

	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);

	task_handoff_unregister(&task_free_nb);

	end_sync();

	mutex_unlock(&buffer_mutex);

	flush_scheduled_work();



	/* make sure we don't leak task structs */

	process_task_mortuary();

	process_task_mortuary();



	free_cpumask_var(marked_cpus);

}